We note that in localized IGrM regions with \(\div {{v}} \ne 0\) , the pollutants may also experience compressions or rarefactions, hence tracing not only smooth bulk processes (subsonic turbulent eddies) but also nonlinear in-situ features (shocks and cold fronts).
In the HD grid simulations, such iron density is implemented via a normalized scalar \(Z \in [0,1]\)  tied to each cell gas density such as \(\rho _Z = Z\,\rho \)  [1]}. Ought to high-order Godunov schemes such as the Piecewise-Parabolic Method (PPM; [2]}) numerical diffusion is kept at low levels compared with physical diffusion, e.g., due to turbulence.
Further, despite the large diversity of elements, IGrM HR numerical studies often use the approximation \(Z \approx Z_{\rm Fe}\) , since iron has one of the strongest line emissions among heavy elements – especially in hot plasma halos – which can be robustly constrained via X-ray spectra (§).
We note that, while metals are a dynamical passive tracer, they contribute significantly to the line cooling of the gas below \(T<1\ {\rm keV}\)  [3]}, hence accelerating the IGrM condensation cascade.
